U.S. President Donald Trump should not mention the example of Libya when he meets with North Korean leader Kim Jong-un to discuss the denuclearization of the regime, a former U.S. envoy said Tuesday.

Robert King, former U.S. special envoy for North Korea human rights, was addressing recent talk about a Libyan style solution to the issue of North Korea's nuclear weapons program, under which the North would be rewarded only after it completely dismantles the facility.

He said the North's current vice foreign minister, Kim Kye-gwan, made it clear to him in a meeting in 2011 that Pyongyang will not follow the example of Libya, whose then leader, Muammar Gaddafi, was months away from being killed by rebel forces.

Gaddafi renounced his nuclear weapons program in 2003.

"One thing is clear: if the United States is to make progress in the denuclearization of North Korea, it would be well to avoid any reference whatsoever to Libya," King said in a piece to the Center for Strategic and International Studies.

"In fact, a productive point of departure in preparing for talks with Kim Jong-un might be to determine how these talks are going to persuade Kim Jong-un that moving forward on denuclearization will not produce a result like Libya," he said.

Trump is due to sit down with Kim before the end of May, although the date and venue have yet to be set.

It would follow a year of tensions over North Korea's nuclear and ballistic missile testing, which the regime has said is aimed at enabling it to strike the U.S. with a nuclear weapon.

"We are on the eve of momentous talks at the highest level between President Trump and leader Kim Jong-un. This could be an opportunity for a historic shift in relations with the DPRK that could make an important difference in Northeast Asia," King said, referring to the North by its official name, the Democratic People's Republic of Korea.

"But it could just as easily turn into an unmitigated disaster with dreadful consequences. There may be an opportunity for a serious conversation, but it needs to be carefully and thoughtfully prepared. Starting at the top doesn't leave any place else to go," he added.